Thomas Assheton Smith (the elder) (1752 – 12 May 1828) was an English landowner and all-round sportsman who played a major part in the development of the Welsh slate industry.

He put down the rioting which resisted exercise of his new rights of control over the commons with the support of a cavalry unit.

By 1826 the Dinorwic Quarry was employing 800 men and producing 20,000 tons of slate per year.

Smith was not a good player, unlike his son, but is known to have taken part in 45 major matches between the 1787 and 1796 seasons.

Assheton Smith's third son, William, saw action at Trafalgar on HMS Temeraire but drowned in 1806.